This invention concerns waste outlets for plumbing systems.
Waste outlets admit waste water form shower cabinets into the waste water pipework. In multi storey buildings a single downpipe or stack may drain a series of showers and toilets. The fluctuations in pressure in the downpipe cause an extractive or draining effect upon the waste outlets. This tends to leave inadequate waste water levels in the outlets.
The existing waste outlets have a spider which retains some hair and soap insolubles. This obliges people to use dangerous cleaning chemicals such as caustic soda. If a blockage then occurs the plumber must deal with a blockage containing a pocket of dangerous chemicals. It would be advantageous to be able to remove the trapped material more easily than retrieving it from the spider. An Australian/New Zealand Standard pertains to waste outlets which some outlets presently fail to meet, namely provision for ensuring adequate water remains to provide the trap.
Australian Patent # 635 613 describes a waste outlet with a central sypherical chamber which houses the water trap but the outlet is on the same axis as the inlet and no provision is made for convenient cleaning.
This invention addresses the above problem.
This invention provides a waste outlet of the type described comprising a bowl with an outlet which is capable of connection to a waste pipe and means to locate the bowl in relation to the surface to be drained, a drainage cover for the bowl and a filter nesting in the bowl which is connected to the cover and removable from the bowl for cleaning.
Preferably the bowl has a mouth which screws into the bowl and the drainage cover seats on the mouth. The mouth may include a seal against the bowl so that a water proof connection is made with the shower tray. The bowl may have a reservoir in which the filter nests immersed and which remains full of water permanently despite pressure changes in the pipes.
The filter may be connected to the mouth so that both lift out seriatim. The filter may also be connected to a strainer which also lifts out, both strainer and filter nesting within the reservoir. The mouth may have a flange which retains the drainage cover. The cover is perforated with drainage apertures which tend to act as a first barrier to hair, labels etc. This may be side receiving rather than top receiving.
The strainer and filter lie almost completely immersed in the waste water of the reservoir. The bowl has an outlet spigot which may be threaded or otherwise prepared to couple with a waste tube. The outlet is separated from the mouth of the bowl by the filter.
One embodiment of the invention is now described by way of example.